13-3r+2+6r-2r-1=3+(2*9)

Solution for 13-3r+2+6r-2r-1=3+(2*9) equation:

Simplifying
13 + -3r + 2 + 6r + -2r + -1 = 3 + (2 * 9)

Reorder the terms:
13 + 2 + -1 + -3r + 6r + -2r = 3 + (2 * 9)

Combine like terms: 13 + 2 = 15
15 + -1 + -3r + 6r + -2r = 3 + (2 * 9)

Combine like terms: 15 + -1 = 14
14 + -3r + 6r + -2r = 3 + (2 * 9)

Combine like terms: -3r + 6r = 3r
14 + 3r + -2r = 3 + (2 * 9)

Combine like terms: 3r + -2r = 1r
14 + 1r = 3 + (2 * 9)

Multiply 2 * 9
14 + 1r = 3 + (18)
14 + 1r = 3 + 18

Combine like terms: 3 + 18 = 21
14 + 1r = 21

Solving
14 + 1r = 21

Solving for variable 'r'.

Move all terms containing r to the left, all other terms to the right.

Add '-14' to each side of the equation.
14 + -14 + 1r = 21 + -14

Combine like terms: 14 + -14 = 0
0 + 1r = 21 + -14
1r = 21 + -14

Combine like terms: 21 + -14 = 7
1r = 7

Divide each side by '1'.
r = 7

Simplifying
r = 7